Protector.



H. G. BANQHELD.

PROTECTOR.

APPLICATIUN ma MAH.B,1915.

h@ Patented Apr. 10, 191:2.

W Wy/1a y nl,

UNITED sTATEs PATENT oEEicE.

HAROLD GILLESPIE BANDFIELD, OF NEW YORK, N. Y., ASSIGN OR, BY MElSNE ASSIGN- MENTS, TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

PROTECTOR.

Application filed March 8, 1915.

BANDFIELD, a citizen of the United States,

residing at New York, in the county of New York and State of New York, have invented certain. new and useful Improvements in Protectors, of which the following is a full, clear, concise, and exact description,

This invention relates to protective devices for electric circuits.

In protective devices commonly used in practice, it is customary to separate the electrodes thereof through the medium of a dielectric spacing material. It is the object of this invention to provide a protective device in which the electrodes thereof are held apart and maintained electrically separate without the use of any spacing means.

A protector embodying the features of this invention may comprise a pair of electrodes positioned to oppose each other, one of which electrodes is comprised of bodies of conducting and non-conducting material, and the other of said electrodes is comprised of a conducting member. An air-gap is formed between said electrodes and they are maintained electrically separate by regimoving a portion of the opposing conductli'ng surface, included between said non-conducting bodies, of either or both of said electrodes.

This'invention is illustrated by the accompanying drawing in which: Figure 1 is a front elevation, partly in section, of a protector made in accordance with this invention; and Figs. 2 and 3 are front elevations of modified forms of the protectors shown in Fig. 1.

A protector embodying the features of this invention is composed of a pair of electrodes 4 and 5, positioned to oppose each other and are retained in this position by means of dowel pins 6, G. The elect-rode 4 has a pori' tion removed at the ends thereof and bodies of insulating material 7, such as fiber, .1nserted therein. The electrode 5 comprises preferably a metallic member. A portion of the opposing surface included between the insulation inserts 7, 7 of the electrode 4 is removed. The corresponding surface of the electrode 5 is likewise removed and these recesses form an air-gap between the conducting surfaces of the electrodes 4 and 5. It is obvious that this air-gap may Specification of Letters Patent.

Patented Apr. 10, 1917.

Serial No. 12,802.

be regulated by removing a greater or smaller amount of the opposing metallic surfaces bounded by the insulation inserts 7, 7. To more prominently define the air-gap formed between the electrodes 4 and 5, a plurality of notches 8, 8 are made transversely in the electrode 5 at points opposite the inner edges of the insulation inserts 7, 7. Thev inner corner portion of the inserts 7, 7 is also removedto' the same depth as that of the recessed conducting porti-on of the electrode 4. The function performed by this arrangement rtends to eliminate any sparking between the opposing metallic portions of the electrodes 4 and 5 at the point where the conducting and non-conducting portions meet, thereby preventing the consequent cabonization of the insulation inserts 7,7, which would naturally result in event only the conducting portion was removed.

In the modified forms of protectors shown in Figs. 2 and 3, the air-gap is formed between the opposing electrodes by removing a portion of the opposing surface of only one of said electrodes. In Fig. 2 the air-gap formed between the electrodes 4 and 5 is obtained by removing the opposing conducting characterized by simplicity of constructionl and efficiency of operation is obtained by virtue of being able to regulate to a marked degree of ineness the air-gap between the op1 osing surfaces of the electrodes of the protector, this latter feature being accom plished without the intervention of a dielc tric spacing material.

What is claimed is:\

1. A protector comprisinga pair of electrodes, one of said electrodes comprisin a.

conducting member, the other of sai'l e`ectrodes comprising a body of conducting material and a body of non-conducting material in fixed relation therewith, the opposing conducting surfaces of said electrodes when placed in opposition to each other being in relatively different planes, whereby an air gap is formed therebetween.

2. protector comprisinga pair of electrodes, one of said electrodes comprising a conductingr block having a depressed portion. the other of Said electrodes comprising bodies o1 conducting and non-conducting material in fixed relation to cach other and in the same plane, whereby when the elec- `trodes are placed in opposition to each other said depressed portion is electrically distinct from said other electrode and positively separated therefrom h v a definite and fixed air gap.

3. protector comprising a pair of electrodes, one o1 said electrodes comprising a body ofl colulucliujdr material having sections of insulating material molded therein, the other of' said electrodes comprising a c0nductingl memher having portions adapted to bear on said insulating sections, whereby saidelectrodes are electrically distinct from each other and the opposing conducting snrfaces are separated by a definite air ga 4. A protector comprising a pair o electrodes, one of said electrodes comprising a conducting block having a depressed portion, the other ot' said electrodes comprising a body of conducting material having insulating material molded therein adapted to provide a bearing surface for said conducting block, whereh)7 when the electrodes are placed in opposition said depressed portion is electrically distinct from said other electrode and positivel)7 separated therefrom by a definite and fixed air gap.

In witness whereof, I hereunto subscribe my name this (5th da \v of March, A. D., 1915.

E. Enum, K. L. STAHL. 

